Safety Issues

While the probability of a nuclear power accident may be small, the human and environmental consequences of a radiation release can be catastrophic.

Nuclear accidents happen

Floods, fires, and earthquakes can combine with aging facilities and error-prone humans in devastating ways. Adequate understanding of these issues, along with significant safety upgrades and consistent oversight, can help safeguard the U.S. public.

Waste should be safely stored

Nuclear fuel emits radiation long after it’s done powering a reactor. Securing a long-term waste repository—and transferring fuel currently held in cooling pools to dry casks—is essential for long-term public safety.

Security matters

The NRC must do more

The Nuclear Regulatory Commission (NRC) is charged with regulating commercial nuclear power in the United States. UCS has been advocating for better NRC enforcement of safety regulations for decades—but more must be done to make nuclear power safer.

Technology

Boiling water with fission

The basic principle behind a nuclear reactor is simple: the heat produced by a controlled nuclear reaction is used to create steam pressure that drives a power-generating turbine.

But the technology required to implement this principle efficiently and safely is enormously complex. The fission chain reaction must be maintained at the correct rate and quickly adjusted or stopped when necessary. Water temperature and pressure must be carefully controlled. And elaborate, redundant cooling systems are needed to prevent nuclear fuel from overheating, which can lead to a meltdown.

PWR vs BWR

Different reactor designs approach these requirements in different ways. About two-thirds of operating U.S. reactors are pressurized water reactors (PWRs); the rest are boiling water reactors (BWRs). Both BWRs and PWRs heat ordinary water with nuclear fuel, driving turbines that generate power.

New designs

Several new reactor designs have been proposed in the United States and elsewhere. These include “small modular reactors” which proponents claim are safer and more cost-effective, but which introduce their own issues. Thorium-fueled reactors have also been proposed, though they lack clear overall advantages.

Regional Work

Concerned about nuclear safety in your neighborhood? Assembled by experts at the Union of Concerned Scientists, our interactive nuclear power database details the safety record of every commercial nuclear reactor in the United States. You can find comprehensive, up-to-date information on fire protection problems, flooding and earthquake risks, recent near-misses, and other nuclear safety issues affecting individual plants and reactors near your community—or view how these issues affect the nuclear fleet as a whole.